{ "id": "1910.04078", "version": "v1", "published": "2019-10-09T15:50:09.000Z", "updated": "2019-10-09T15:50:09.000Z", "title": "Equivalence and finite time blow-up of solutions and interfaces for two nonlinear diffusion equations", "authors": [ "Benito Hernández-Bermejo", "Razvan Gabriel Iagar", "Pilar R. Gordoa", "Andrew Pickering", "Ariel Sánchez" ], "categories": [ "math.AP" ], "abstract": "In this work, we construct a transformation between the solutions to the following reaction-convection-diffusion equation $$ \\partial_t u=(u^m)_{xx}+a(x)(u^m)_x+b(x)u^m, $$ posed for $x\\in\\real$, $t\\geq0$ and $m>1$, where $a$, $b$ are two continuous real functions, and the solutions to the nonhomogeneous diffusion equation of porous medium type $$ f(y)\\partial_{\\tau}\\theta=(\\theta^m)_{yy}, $$ posed in the half-line $y\\in[0,\\infty)$ with $\\tau\\geq0$, $m>1$ and suitable density functions $f(y)$. We apply this correspondence to the case of constant coefficients $a(x)=1$ and $b(x)=K>0$. For this case, we prove that compactly supported solutions to the first equation blow up in finite time, together with their interfaces, as $x\\to-\\infty$. We then establish the large time behavior of solutions to a homogeneous Dirichlet problem associated to the first equation on a bounded interval. We also prove a finite time blow-up of the interfaces for compactly supported solutions to the second equation when $f(y)=y^{-\\gamma}$ with $\\gamma>2$.", "revisions": [ { "version": "v1", "updated": "2019-10-09T15:50:09.000Z" } ], "analyses": { "keywords": [ "finite time blow-up", "nonlinear diffusion equations", "interfaces", "equivalence", "compactly supported solutions" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }